Wild elephants are some of the most caring and intelligent animals on our planet. They express sadness and happiness almost as deeply as humans. They are truly majestic animals which should be held in the highest regard. But there is still so much that is not known about them. Their sleep patterns in the wild are a complete unknown, for example.
All prior studies that were conducted on this matter were done using elephants that were held in captivity, where outside factors were much different. When they are in captivity there is much less interaction with other animals, especially predators. Searching for water and food is also an activity that captive elephants do not have to be bothered with. And this is a big thing, especially for animals that consume more than a few hundred pounds of food each day.
During a study performed on two herd matriarchs in the Chobe National Park, scientists for the first time learned in more detail how elephants really rest in the wild. During the month-long study, they followed the two female elephants that lead their herds and learned that the elephants in the wild sleep for two hours a night on average. Interestingly, the elephants even had five days when they did not sleep at all. If further studies show that wild elephants really do sleep like this all the time, it means that they sleep less than any other mammal.
Scientists have been observing elephants for close to 80 years now. The issue was, as we previously stated, that the elephants observed were in captivity. The elephants that they observed were either in zoos or in circuses. Here there is no threat from lions or other predators and water is plentiful. Without these factors, the researchers noted that elephants slept anywhere from five to seven hours each day. This is more in line with other mammals out there. In the wild other mammals probably sleep less as well, there just isn’t enough information out there to make an accurate assumption.
Scientists did think the elephants in the wild sleep for short periods of time, around three hours, but even they were surprised to learn that number is closer to two. The biggest issue when monitoring the sleep pattern in elephants is how they sleep. Sometimes the elephants sleep while standing up. It is much easier when they lay down since that is a clear indicator. Because of this, scientists developed a new method for monitoring when elephants sleep. If the elephant’s trunk stays still for more than five minutes the scientists consider they are getting some quality rest in.
In order to achieve this, the scientists implanted activity trackers in elephant trunks. For those wondering, the procedure for implementation of the activity loggers is in no way invasive.
During the study performed on the two matriarchs, they noticed that one slept for around 2.3 hours a day, while the other slept for 1.8 hours. On average, the two elephants slept two hours a night. What is even more interesting they did not sleep for two hours in one go. They usually divided these into five sleeping spells each night. And this all occurred during the period between 1 a.m. and 6 a.m.
But the most interesting day was when the two matriarchs combined for more than 45 hours without sleep. What is even more interesting is that the elephants weren’t just awake, they were actively moving. One of the matriarchs covers about 15 miles, while the other one traveled a whopping 20 miles.
The elephant’s brains contain a cluster of cells, the orexinergic nuclei, that are directly connected to sleep and safety. If they do not have enough to eat these nuclei keep the elephant awake until they are full and then they are able to sleep. Horses are similar in this regard as they sleep three hours, but gray whales, for example, sleep at least nine hours a day.